How to zoom a Photo Editor view?

Question

I am using a library for Image Editor. This library works well. I get whatever I want except the zooming functionality. This is my xml code:

<ja.burhanrashid52.photoeditor.PhotoEditorView
        android:id="@+id/editorView"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        app:layout_constraintTop_toBottomOf="@id/toolbar"
        app:layout_constraintBottom_toTopOf="@id/bottomView"
        android:visibility="visible" />

I tried using this code but it only zooms the image view. Ie the source by doing getSource(). This is the code I tried:

// in my class
Matrix matrix = new Matrix();
    Matrix savedMatrix = new Matrix();

    // We can be in one of these 3 states
    static final int NONE = 0;
    static final int DRAG = 1;
    static final int ZOOM = 2;
    int mode = NONE;

    // Remember some things for zooming
    PointF start = new PointF();
    PointF mid = new PointF();
    float oldDist = 1f;
    String savedItemClicked;
    private String TAG = "ImageEditorActivity";

// in the onCreate


binding.editorView.getSource().setScaleType(ImageView.ScaleType.MATRIX);
        binding.editorView.getSource().setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                // TODO Auto-generated method stub

                ImageView view = (ImageView) v;
                dumpEvent(event);

                // Handle touch events here...
                switch (event.getAction() & MotionEvent.ACTION_MASK) {
                    case MotionEvent.ACTION_DOWN:
                        savedMatrix.set(matrix);
                        start.set(event.getX(), event.getY());
                        Log.d(TAG, "mode=DRAG");
                        mode = DRAG;
                        break;
                    case MotionEvent.ACTION_POINTER_DOWN:
                        oldDist = spacing(event);
                        Log.d(TAG, "oldDist=" + oldDist);
                        if (oldDist > 10f) {
                            savedMatrix.set(matrix);
                            midPoint(mid, event);
                            mode = ZOOM;
                            Log.d(TAG, "mode=ZOOM");
                        }
                        break;
                    case MotionEvent.ACTION_UP:
                    case MotionEvent.ACTION_POINTER_UP:
                        mode = NONE;
                        Log.d(TAG, "mode=NONE");
                        break;
                    case MotionEvent.ACTION_MOVE:
                        if (mode == DRAG) {
                            // ...
                            matrix.set(savedMatrix);
                            matrix.postTranslate(event.getX() - start.x, event.getY()
                                    - start.y);
                        } else if (mode == ZOOM) {
                            float newDist = spacing(event);
                            Log.d(TAG, "newDist=" + newDist);
                            if (newDist > 10f) {
                                matrix.set(savedMatrix);
                                float scale = newDist / oldDist;
                                matrix.postScale(scale, scale, mid.x, mid.y);
                            }
                        }
                        break;
                }

                view.setImageMatrix(matrix);
                return true;
            }

            private void dumpEvent(MotionEvent event) {
                String names[] = { "DOWN", "UP", "MOVE", "CANCEL", "OUTSIDE",
                        "POINTER_DOWN", "POINTER_UP", "7?", "8?", "9?" };
                StringBuilder sb = new StringBuilder();
                int action = event.getAction();
                int actionCode = action & MotionEvent.ACTION_MASK;
                sb.append("event ACTION_").append(names[actionCode]);
                if (actionCode == MotionEvent.ACTION_POINTER_DOWN
                        || actionCode == MotionEvent.ACTION_POINTER_UP) {
                    sb.append("(pid ").append(
                            action >> MotionEvent.ACTION_POINTER_ID_SHIFT);
                    sb.append(")");
                }
                sb.append("[");
                for (int i = 0; i < event.getPointerCount(); i++) {
                    sb.append("#").append(i);
                    sb.append("(pid ").append(event.getPointerId(i));
                    sb.append(")=").append((int) event.getX(i));
                    sb.append(",").append((int) event.getY(i));
                    if (i + 1 < event.getPointerCount())
                        sb.append(";");
                }
                sb.append("]");
                Log.d(TAG, sb.toString());
            }

            /** Determine the space between the first two fingers */
            private float spacing(MotionEvent event) {
                float x = event.getX(0) - event.getX(1);
                float y = event.getY(0) - event.getY(1);
                return (float) Math.sqrt(x * x + y * y);
            }

            /** Calculate the mid point of the first two fingers */
            private void midPoint(PointF point, MotionEvent event) {
                float x = event.getX(0) + event.getX(1);
                float y = event.getY(0) + event.getY(1);
                point.set(x / 2, y / 2);
            }
        });